Toggle lever press



March 23, 1965 o. MAY

TOGGLE LEVER PRESSl 2 Sheets-Sheet 1 Filed May 19, 1961 A T TORNEYS March 23, 1965 o. MAY 3,174,560

TOGGLE LEVER PRESS Filed May 19, 1961 Y 2 Sheets-Sheet 2 United States Patent Oh ice 3,174,560 TGGGLE LEVER PRESS Otto May, Stuttgart, Germany, assigner to May- Pressenoan Ltd., Schwabisch-Gmund, Germany Filed May 19, 1961, Ser. No. 111,393 6 Claims. (Cl. 173-150) The present invention relates to a stoggie lever press having a reciprocating main ram, and has the main object of providing a press of this kind wherein it is possible to bring the press tool and the work piece accurately into alignment with one another with the aid of simple means.

lt is another object of the invention to dispense with any movement of the work piece transversely of the axial di.- rection of the said main ram.

It is another object of the invention to provide a press of the kind referred to, the total working stroke of which is prolonged in such a manner as to suffice for the pressing even of comparatively deep cup-shaped work pieces.

With these and other objects in view which will become apparent later from this speciiication and the accompanying drawings, I provide a toggle lever press comprising in combination: a frame, a main ram, guided axially reciprocating in the said frame, and an auxiliary member capable of carrying a tool and/or work piece, movable relative to the said main ram in the axial direction thereof.

Preferably this auxiliary member is movable automatically into predetermined positions in dependence of the positions of the main ram. It is then advantageous it" the auxiliary member is moved by means of a pressure fluid.

A particularly favourable construction results, when the auxiliary member is an auxiliary ram, which is movable inthe axial direction in the main ram.

Conveniently the auxiliary ram is capable of being advanced from the extreme outer position of the main ram, and ot being retracted from the extreme inner position of the main ram. Advantageously the auxiliary ram is lockable in the foremost position relative to the main ram.

A favourable construction results, when in the main ram auxiliary pistons are provided, which are controlled by the pressure uid and by means of which the auxiliary ram can be advanced or retracted, respectively, in the axial direction.

Conveniently on the main ram a piston operated by the pressure iluid is provided, by means of which the locking device is controlled.

Embodiments of the invention are illustrated by way of example in the accompanying drawings, in which:

FIG. l is a longitudinal part-section on the line 1 1 of FIG. 2 of a first embodiment of the invention, the main ram being illust-rated in the extreme outer position, and the auxiliary ram in the retracted position;

FIG. 2 is a plan-view, partly broken away, of the press according to FG. l;

FIG. 3 is a horizontal longitudinal section on the line 3-3 ot the press :according to FIG. l;

FIG. 4 is a horizontal longitudinal section like FIG. 3, however with the main ram in the extreme inner position and with the auxiliary r-arn in the advanced position;

FlGS. 5 to 8 are diagrammatic illustrations of the most important positions of the main and auxiliary rams of the press according to FIGS. l to 4;

FIG. 9 is a longitudinal section of a second embodiment of the invention, the main ram being illustrated in the extreme outer position, and the auxiliary ram in the retracted position.

In the embodiment according to FIGS. l to 4 a horizontal toggle lever press is illustrated having a press frame 12 resting at 121 and 122 on a foundation not illustrated l'dh@ Patented Mar.. 23, 1965 in more detail. The press frame 12 has a table 127 and a press casing 123, in which a reduction gearing is housed. A main ram 13 is slidable in guide tracks 124 of the press frame.

The drive of the press is effected through a V-belt pulley 14, which may be driven through a V-belt from an electric motor (not shown). On the shaft l5 of the V-belt pulley journalled in the press casing 123 a pinion 16 is rigidly mounted, which meshes with a gear wheel 18 fixed to a shaft 17. 0n the shaft 17 a pinion 19 is 4rigidly mounted, which is in mesh with a gear wheel 21 restrained from turning relative to a shaft 20. Through two equal ear wheels 22 rigidly mounted on the shaft 2@ the drive of two large gear wheels 23 is effected, which are mounted on a crank disc shaft 2li journalled in the press casing 12. On the same shaft the crank discs 11 are rigidly mounted, which are articulated each to a connecting rod 26 by means ot a crank pin 25. The two connecting rods 26 are each articulated by means of a connecting rod pin 27 to a short toggle lever 3i? in turn articulated to a stationary pivot pin 28 i'ixedly mounted in the press table 127 and penetrating through this press table 127. By means of a knee joint pin 29 penetrating through arcuate recesses in the press casing 123 the two short toggle levers 3l) .are connected to one another. On the projecting ends of this knee joint pin 29 long toggle levers 31 are articulated, which are retained on the knee joint pin 29 by means of washers 32 and screws 33. The other ends of the two long toggle levers 31 are each articulated to a hinge pin 34 ixedly mounted on the main ram 13, and are retained on the same by means of washers 3S and screws 36.

As already mentioned, the main ram 13 can slide along the guide tracks 124i of the press frame 12. In the Ipress frame 12 recesses 12d are arranged on both sides of the main ram 13, into which extend the projections 131 of the main ram 13. On the outer faces 132 of the projections 131 the long toggle levers 31 may slide in the operation of the press.

In the main ram 13 an auxiliary ram 37 is mounted longitudinally slidable. On its forward portion a tool carrier head 371 is provided for taking in tools 48 (see FIGS. 5 to 8). For the drive of the auxiliary ram 37 piston rods 33 are rigidly attached on both sides of the tool car- -rier head 371 the ends of which carry pistons 39, which are slidably fitted into cylinders provided in the main ram 13.

These cylinders are divided by the pistons 39 into two chambers dill and 402, into which the ducts (not shovm in the drawing) issue for the supply and drainage, respectively, of a pressure iiuid.

For locking the auxiliary ram 37 to the main ram 13 a special device is provided which is operable by a piston 41 having a piston rod e2. The piston il is slidably arranged in an extension 133 of the main ram 13 having a cylinder bore. The cylinder space is divided by the piston 41 into two chambers 431 and 4.32, which are connected to ducts (not shown in the drawings) for the supply or drainage, respectively, of a pressure ihu'd.

The piston rod ft2 is connected to a double lug 43, at each end of which a lever 4.5 is articulated, which is rigidly fixed to a pin ftd. The two pins 44 are rotatably mounted in the main ram 13 and carry at their lower ends two locking pawls de arranged diametrically opposite ot one another, which are capable of engaging into recesses 372 of the auxiliary ram 31' in a certain position of the latter.

The manner of operation of the press according to FIGS. 1 to 4 is as follows:

When the V-belt pulley 1d rotates, the drive of the two crank discs 11 is effected through the pinion i6, gear o wheel 18, pinion 19, gear Wheel 21 and the two gear wheels 227 which mesh with the large gear wheels 23. Upon rotation of the crank discs 11 the short toggle levers 31B are rocked to-and-fro about the stationary pivot pins 28 by the aid of the connecting rods 26. Thereby also the knee joint pin 29 is moved to-and-fro and the main ram 13, is reciprocated in the axial direction in the guides 124 of the press frame 12 by means of the long toggle levers 31.

The relative movements of the auxiliary ram 37 with respect to the main ram are effected by the pistons 39 arranged in the main ram, the spaces 402 of the cylinders being supplied with pressure fluid for the forward stroke of the auxiliary ram, and the spaces 401 at its return stroke. The transmission of the piston movements to the auxiliary ram 37 is effected through the piston rods 38, which are rigidly connected to the tool carrier head 371 of the auxiliary ram 37.

The locking and unlocking of the auxiliary ram 37 in its advanced position is effected by the piston 41 which is moved in one direction or the other by the supply of pressure fluid to the chamber 431 or 432, respectively. When the piston 41 is in the position according to FIG. 1, the pins 44 are turned by means of the piston rods 42 and the double lug 43 in such a manner, that the pawls 46 are swung outward and the auxiliary ram 37 is completely unlocked.

In the position according to FIG. 4 the main ram 13 is in its innermost position, and the auxiliary ram 37 is illustrated in its foremost position. In this position, the

auxiliary rarn may be locked. This is effected in that the piston 41 is supplied with pressure fluid through the chamber 432, so that it is pushed into the position shown in FIG. 4.

The piston rod 42 then pulls the double lug 43 back, so that the pins 44 are turned by the levers 45. Thereby the locking pawls 46 are turned so as to engage the recesses 372 of the auxiliary ram 37, whereby the auxiliary ram 37 is interlocked with the main ram 13.

In FIGS. to 8 various working positions of the main ram 13 and the auxiliary ram are illustrated diagrammatically.

In FIG. 5 the main ram 13 is shown in its extreme outer position, and the auxiliary ram 37 in the completely withdrawn position. The auxiliary ram 37 is then unlocked. Then a work piece, for example a cup 47, may be pushed over the mandrel 48, since the same is in its extreme outer position.

As soon as the work piece 47 is tted, the auxiliary ram 37 moves forward with the cup 47.` The end of this next phase is illustrated in FIG. 6. The main ram is still substantially in its extreme outer position, while the auxiliary ram has moved into its foremost position and is then locked.

Now the working stroke of the auxiliary ram in unison with the main rarn may begin. FIG. 7 shows the main ram in its innermost position at the end of a working stroke, the bottom of a cup 47 having just been pressed during this working stroke.

After the pressing operation proper the auxiliary ram 37 is again retracted into the main ram 13, as shown in FIG. 8. Before the retraction, the unlocking of the auxiliary ram is effected in the manner described hereinabove. When the auxiliary ram has arrived in its retracted position, the main ram is practically still in its extreme inner position. During the next subsequent phase of the working cycle, i.e. during the return stroke of the main ram and of the auxiliary ram in unison, the work piece 47 may be removed.

In FIG. 9 a further embodiment of the invention is illustrated. In a press frame 61B of an upright toggle lever press with a table 607 a main ram 61 is arranged longitudinally slidable in guides 6&4. On both sides of the main ram two hinge bolts 62 are provided to which the first toggle levers 63 are articulated.

The latter are connected to a knee joint pin 64 on which the second toggle levers 65 are articulated, which embrace the toggle levers 63 fork-fashion. Between the second toggle levers 65 a sleeve 66 is arranged on the knee joint pin 64. The upper ends of the second toggle levers65 are articulated on a stationary pivot pin 67.

The drive of the two toggle lever systems is not illustrated in the drawing. It may be effected in the usual way in such a manner that by means of a lug on the sleeve 66 the toggle levers are stretched during the working stroke, and are folded during the idle stroke.

In the main ram 61 the auxiliary ram 69 is slidably fitted, which can be pushed forward and back, respectively, by means of pistons movable in corresponding cylinder spaces provided in the main ram. This driving arrangement corresponds substantially to that shown in FIGS. l to 4, and is not illustrated in FIG. 9.

The locking is effected by means of a piston 70 which is movable in a cylinder space of an extension 611 of the main ram 61. The piston rod 71 attached to the piston 70 is connected to a double lug 72 to which two levers 74 are articulated each of which is xed to a pin 73. On the other ends of the pins 73 locking pawls 75 are fixed, which in the forward position of the auxiliary ram 69 may engage into recesses 691 of the auxiliary ram.

Otherwise the Working cycle of the press illustrated in FIG. 9 is the same as that described with reference to the embodiment illustrated in FIGS. l to 4.

While I have described herein and illustnated in the accompanying drawings what may be considered typical and particularly useful embodiments of my said invention I wish it to be understood that I do not limit myself to the particular details and dimensions described or illustrated; for obvious modifications will occur to a person skilled in the art.

What I claim as my invention and desire to secure by -Letters Patent is:

1. A toggle lever press comprising a frame extending along an axis; a main ram mounted in said frame guided `axially along said axis, means for reciprocating said main ram between an inner and an outer position; an auxiliary ram coaxial to and cooperating with said main ram; guidmg members for said auxiliary ram; means for reciprocating said auxiliary ram between a retracted and an advanced position relative to said main ram, having la longer actuating stroke than that of said reciprocating means of said main ram; said auxiliary ram having at its outer surface recesses located diametrically opposite one another; locking means having movable pawls engaging with said recesses for locking said lauxiliary ram in its advanced position before said main ram has reached said inner position and disengaging after said main ram has emerged from said inner position; auxiliary members for moving said locking means between a locking position and a releasing position comprising a double-acting pressure cylinder mounted on said guiding members for said auxiliary ram and a piston connected to said locking means.

2. A toggle lever pressaccording to claim l, wherein said cylinder is mounted on said main ram.

3. A toggle Alever press according to claim l, wherein said main ram forms said guiding members for said auxiliary ram.

4. A toggle lever press according to claim 3, wherein said means for reciprocating said auxiliary ram are mounted on said main ram.

5. A toggle lever press according to claim l, wherein axis bolts of said locking means are provided mounted `on said main ram.

6. A toggle lever press according to claim 5, wherein said auxiliary members for moving said locking means -are mounted on said main ram.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS Hnde 113-45 Wilzin 11345 Patrick 113-3 8 Jacoby 113-38 Patrick 113-38 Neson 113-3 8 6 FOREIGN PATENTS 1,077,436 4/54 France.

Examiners. 

1. A TOGGLE LEVER PRESS COMPRISING A FRAME EXTENDING ALONG AN AXIS; A MAIN RAM MOUNTED IN SAID FRAME GUIDED AXIALLY ALONG SAID AXIS, MEANS FOR RECIPROCATING SAID MAIN RAM BETWEEN AN INNER AND AN OUTER POSITION; AN AUXILIARY RAM COAXIAL TO AND COOPERATING WITH SAID MAIN RAM; GUIDING MEMBERS FOR SAID AUXILIARY RAM; MEANS FOR RECIPROCATING SAID AUXILIARY RAM BETWEEN A RETRACTED AND AN ADVANCED POSITION RELATIVE TO SAID MAIN RAM, HAVING A LONGER ACTUATING STROKE THAN THAT OF SAID RECIPROCATING MEANS OF SAID MAIN RAM; SAID AUXILIARY RAM HAVING AT ITS OUTER SURFACE RECESSES LOCATED DIAMETRICALLY OPPOSITE ONE ANOTHER; LOCKING MEANS HAVING MOVABLE PAWLS ENGAGING WITH SAID RECESSES FOR LOCKING SAID AUXILIARY RAM IN ITS ADVANCED POSITION BEFORE SAID MAIN RAM HAS REACHED SAID INNER POSITION AND DISENGAGING AFTER SAID MAIN RAM HAS EMERGED FROM SAID INNER POSITION; AUXILIARY MEMBERS FOR MOVING SAID LOCKING MEANS BETWEEN A LOCKING POSITION AND A RELEASING POSITION COMPRISING A DOUBLE-ACTING PRESSURE CYLINDER MOUNTED ON SAID GUIDING MEMBERS FOR SAID AUXILIARY RAM AND A PISTON CONNECTED TO SAID LOCKING MEANS. 